Radiant Heat Circulation Pump?

Discussion in 'Boiler Forum' started by Ferretman, Mar 26, 2014.

  1. Ferretman

    Ferretman New Member

    Messages:
    4
    Location:
    Colorado
    Looking for folks' thoughts on this.

    I had the boiler on my radiant heat system stop working the other day and when I investigated quickly figure out why--four of the main feeder lines had air in them!

    A quick call to and visit by a local radiant heat specialist resulted in his opinion that the guys who installed the system hadn't properly bled it out, and so over time the air collected and coalesced and then one day *boom*....pressure was too low for the system to operate properly. He filled it all up, we restarted the system and things seemed goodly.

    However, after a couple of days I noticed that my energy draw (I'm off-grid) was still much higher than it had been prior to all this fun. I expected higher usage while the system got the house back up to temperature but it was at that according to all of the thermostats and usage was still higher than I would have expected. As I was poking around the installation I realized that the circulation pump (a Grundfos) is VERY hot. The fluid (glycol) is set to 130[SUP]o[/SUP] F and I can easily put my hand on the copper manifold coming out of the boiler, but that pump is way hot--you can't keep you hand on it at all.

    My thinking is that the pump may have run dry for a day or two before I noticed the overall problem, and that's why it's running hot and using energy--it has unfortunately been damaged.

    What do folks think? I can honestly note that I don't ever recall laying my hands on that pump before all this, but I'm sure I must have and would have remembered it being this hot....so I'm afraid damage seems my most likely situation. :(


    Steve
    From the High, Snowy Mountains of Colorado
    Last edited: Mar 26, 2014
  2. Tom Sawyer

    Tom Sawyer In the Trades

    Messages:
    3,267
    Location:
    Maine

    They run pretty hot. Check the running amps of the motor and compare with the rating of the motor but generally, with that type of circulator, they either run or they're broken.
  3. Ferretman

    Ferretman New Member

    Messages:
    4
    Location:
    Colorado
    Okay, that's good to know. If so I'm just surprised that I would have not noticed it before.

    Still collecting data. It was interesting to learn that the new glycol the worker came to install was blue instead of pink, the original fluid. He said that McDonald's had bought the rights to exclusive use of the pink stuff, so now my fluid is a kind of purple...

    Better than pink I guess, if one must choose.....


    Steve
    From the High, Snowy Mountains of Colorado
Similar Threads: Radiant Heat
Forum Title Date
Boiler Forum Radiant Heat Leak? Feb 22, 2014
Boiler Forum Radiant heat zone not letting water flow Feb 1, 2014
Boiler Forum Radiant Ceiling Heat Jan 4, 2014
Boiler Forum Radiant Heat, Pex Supplier, Parts, Outdoor Boiler Insulated Line Aug 17, 2012
Boiler Forum Tankless WH Radiant Floor Heat Mar 11, 2012

Share This Page